Neurofibromatosis 1 (NF1), neurofibromatosis 2 (NF2), and schwannomatosis are a group of related neurogenetic tumor suppressor syndromes that share a predisposition to develop nerve sheath tumors. Because most tumors encountered in patients with NF1, NF2, and schwannomatosis are histologically benign, overall survival is not an appropriate clinical trial outcome for these patients. In 2011, a group of NF researchers agreed to meet periodically to develop novel outcomes for these conditions. The Response Evaluation in Neurofibromatosis and Schwannomatosis (REiNS) International Collaboration consists of specialists from multiple countries and disciplines dedicated to the study of neurofibromatosis, schwannomatosis, and clinical trials. REiNS holds an annual conference during the winter in which recommendations for clinical trial outcomes are discussed. Each year, the Leadership Group of REiNS selects experts on the topics under discussion to present the recommendations of each working group for discussion by the larger group. These meetings have led to multiple publications that have been incorporated into ongoing clinical trials and that have been published in the peer-reviewed literature. The annual REiNS meeting is a critical forum for generating new ideas and approaches to these rare tumor suppressor syndromes. The 2015 conference topic is Developing Endpoints to Facilitate Clinical Trials in Rare Diseases and will include outside speakers from the Food and Drug Administration, the Cancer Therapy Evaluation Program, the Children's Tumor Foundation, and the National Cancer Institute.